@mysy
That's the correct file for Nuvi xx series for the NA 2013.40. Have you placed it correctly:
unit:\.system\JCV\D3478070A.JCV
or
SD:\Garmin\JCV\D3478070A.JCV

Not many junction views on that file, so simulate a route from a large city such as LA or NY outbound along a major freeway then scroll thru the route to find a jv.

Your unit does not support 3D or SID or any other extras, except POIs such as speed and redlight alerts etc.